Well tools



Sept. 20, 1966 c. F. BARNARD WELL TOOLS 5 Sheets-Sheet 1 Filed July 8, 1963 FIG. 2

IN VEN TOR.

CHARLES F. BARNARD A uz W FIG. I

Sept. 20, 1966 c. F. BARNARD WELL TOOLS 5 Shee ts-Sheet 2 Filed July 8, 1965 INVENTOR.

CHARLES F. BARNARD BY 4% W6? United States Patent 3,273,648 WELL TOOLS Charles F. Barnard, 3116 Carutll Blvd, Dallas, Tex. Filed July 8, 1963, Ser. No. 293,456 Claims. (Cl. 166-175) This invention relates to well tools and more particularly to a well tool reciprocably longitudinally movable in a flow conductor for preventing formation of deposits on, and removing deposits from, the internal surfaces of the flow conductor or for staging or segmenting the column of fluids in the flow conductor and to a well tool assembly employing such well tool.

An object of the invention is to provide a new and improved well tool vertically and reciprocably movable in a well flow conductor by the fluids flowing through the well flow conductor which removes deposits from the well flow conductor during such movement and which closes the internal passage of the flow conductor to prevent or reduce flow of fluids therepast in the tubing during its movement in one direction in the tubing and perrnits flow of fluids therepast in the tubing during its movement in the opposite direction in the tubing.

Another object is to provide a well tool of the type described having a body provided with a by-pass flow passage and valve means for closing the by-pass flow passage whereby fluids flowing upwardly in the well flow conductor move the well tool upwardly in the flow conductor when its valve means is in closed position and flow of fluids in the tubing past the body is thus prevented or restricted and whereby the well tool falls by gravity downwardly in the flow conductor when its valve means is in open position and flow of fluids in the flow conductor can take place through the by-pass flow passage.

Still another object is to provide a well tool of the type described wherein the well tool is provided with means for moving its valve means between its open and closed positions.

A further object of the invention is to provide a well tool assembly having an elongate flow conductor and a plurality of well tools reciprocably movable vertically through predetermined ranges in the flow conductor wherein each of the well tools substantially closes the flow passage of the flow conductor and has a by-pass flow passage, valve means for closing the bypass flow passsage and opera-tor means for moving the valve means between its open and closed positions, the well tool assembly having stop means engageable with said operator means for moving the valve means to its closed and open positions and thus controlling the reciprocable movement of the well tool in the flow conductor.

A still further object is to provide a well tool assembly of the type described wherein the well tool assembly includes an elongate member or rod string movable reciprocably in the flow conductor providing the stop means and the well tools are movably mounted on the elongate member between the stop means thereof.

Another object is to provide a new and improved well tool mountable on the sucker rod of a string of sucker rods reciprocably movably extending through a well flow conductor, such as a string of tubing, for actuating a pump to move fluids upwardly through the tubing wherein the well tool is reciprocable on the sucker rod and in the tubing during the pumping operations to prevent deposition and accumulation of such substances as paraflin on the internal walls of the tubing.

Another object is to provide a new and improved well tool, movably mountable on the shank of a conventional sucker rod for reciprocatory movement on the shank between a pair of vertically spaced stop surfaces of the rod, having a body which closes the annulus between the shank and the tubing, a by-pass flow passage for allowing flow of fluid through the tubing past the body, and a valve means actuable when the well tool is engaged 'by the lower stop surface of the rod to close the by-pass flow passage whereby the fluid flowing upwardly through the tubing moves the well t-ool upwardly the full length on the shank until it reaches the upper stop surface of the rod whereupon the valve means is actuated to open the by-pass flow passage and permit the well tool to move downwardly by gravity through the tubing until the valve means is again closed as the well tool reaches its lowermost position relative to the shank and its valve means is again actuated to close the by-pass flow passage.

Still another object is to provide a well tool of the type described having a 'body mounted on a shank of a sucker rod for longitudinal movement thereon which substantially closes the annulus between the sucker rod shank and the well flow conductor and has a by-pass flow passage closable by a valve whereby the well tool is movable upwardly in the tubing and on the shank by the liquid being pumped upwardly in the well flow conductor when the valve is closed and which moves downwardly by gravity in the tubing relative to the shank when the valve is open to permit the pumped fluid to flow past the Well tool through the by-pass flow passage.

A further object is to provide a well tool assembly including a string of sucker rods having a plurality of the well tools mounted at longitudinally spaced locations thereon to stage or segment the column of well fluids in the tubing and prevent the condition known as gas lock, which occurs when large columns or bubbles of gas form in the tubing between columns or slugs of liquids and cause a pressure balance condition to occur between the earth formation from which the fluids are being produced so that the compression and expansion of the gas in such large pockets prevents pumping of such fluids through the tubing.

A still further object is to provide a well tool of the type described having a body provided with a central longitudinal bore of greater diameter than the shank of the rod on which it is mountable, a pair of diametrically opposed longitudinally spaced longitudinal slots and a transverse slot connecting inner ends of the longitudinal slots to form a by-pass flow passage through the body, wherein the body is provided with a reciprocable valve slidably mounted thereon and having operator means eX- tending above and below the body for engagement with the upper and lower stop surfaces of a sucker rod whereby the valve is moved to its lower open position on the body when the body reaches an uppermost position on the shank of the sucker rod and the operator means engages the upper stop surface and is movable to closed position when the body attains its lowermost position on the shank and the operator means engages the lower stop surface of the rod.

Still another object is to provide a device of the type described wherein the pressure of the fluids in the tubing exerts no force on the valve tending to move the valve to its open position.

Another object is to provide a Well tool assembly having an elongate flow conductor provided with longitudinally spaced stop means therein and a plurality of the well tools movably disposed in the flow conductor between adjacent pairs of the stop means for movement therebetween wherein each of the well tools substantially closes the longitudinal flow passage of the flow conductor and has a by-pass flow passage and valve means for closing the by-pass flow passage whereby the well tool is moved up wardly in the well flow conductor by the fluids flowing upwardly therethrough when its valve means closes its bypass fl'ow passage and which moves downwardly in the flow conductor when its valve means is in its open position and fluids in the flow conductor flow past the well tool through the bypass flow passage.

' through the tubing to the surface of the well.

Still another object is to provide a well tool assembly of the type described wherein each of the well tools has operator means engageable with the pair of stop means of the flow conductor between which it is movable for moving the valve means to its open position when the well tool reaches the upper stop means and for moving the valve means to its closed position when the well tool reaches the lower stop means.

Additional objects and advantages of the invention will be readily apparent from the reading of the following description of a device constructed in accordance with the invention, and reference to the accompanying drawings thereof, wherein:

FIGURE 1 is a vertical partly sectional view of a well tool assembly including a string of sucker rods disposed in the tubing of a well and the well tool of the invention positioned on the shank of a sucker rod with its valve in closed position and moving upwardly in the tubing relative to the shank;

FIGURE 2 is an enlarged side view showing the well 'tool on the shank of a sucker rod and with its valve in closed position;

FIGURE 3 is a view similar to FIGURE 2 showing the valve in its open position;

FIGURE 4 is a sectional view taken on line 44 of FIGURE 3;

FIGURE 5 is a sectional view taken on line 55 of FIGURE 3;

FIGURE 6 is an exploded perspective view of the well tool;

FIGURE 7 is a fragmentary side view showing the manner in which the well tool is pivoted about the shank of a sucker rod through the opposed longitudinal slots of its body into alignment with the transverse slot thereof during the installation on or removal from a sucker rod of the well tool;

FIGURE 8 is a vertical partly sectional view of a well tool assembly including a string of tubing having longitudinally spaced stop rings and a modified form of the well tool movably disposed in the tubing between each pair of stop rings;

FIGURE 9 is a sectional view taken on line 99 of FIGURE 8; and,

FIGURE 10 is an exploded perspective view of the well tool illustrated in FIGURES 8 and 9.

Referring now to the drawings, the well tool assembly includes a string S of sucker rods 16 reciprocably 'm-ovably disposed in a well flow conductor, such as a tubing T, and having well tools 18 movably mounted on the shanks 19 of the sucker rods. The sucker rod string is reciprocable in the tubing to actuate a pump which pumps or moves the well liquids, such as oil, upwardly The tubing may be formed of the usual tubing sections 20 connected at their ends by the couplings 21. The sucker rods may be of the conventional type being provided with upper and lower wrench portions 24 adjacent each end which are substantially square in cross-section so that the sucker rods may be engaged by wrenches during the connection thereof to one another by the usual internally threaded tubular couplings 26 into which are threaded the end pins 27 of adjacent rods. Upper and lower upsets 28a and 28b provide the outwardly flared stop surfaces 29a and 29b at opposite ends of the shank '19 of each rod.

The well tool 16 comprises a substantially tubular body '32 of slightly resilient substance, such as rubber, nylon and the like, and has a longitudinal bore 33 extending therethrough in which is receivable the shank 19 of the sucker rod. The diameter of the longitudinal bore 33 being greater than the diameter of the shank, the body open through the opposite ends of the body and whose adjacent inner ends are connected by a substantially transversely extending slot 38. The upper longitudinal slot 36 is defined by the vertical side surfaces or walls 36a and 36b which diverge laterally outwardly from the central longitudinal bore 33 so that the slot 36- is narrower in width at its inner end portions than at its outer end and so that the inner end portions of the slot are of narrower width than the diameter of the shank 19. The vertical surfaces or walls 37a and 37b of the body defining the lower longitudinal slot 37 similarly extend divergently outwardly from the longitudinal bore of the body and their inner end portions are of lesser width than the diameter of the shank 19 of the sucker rod on which they are to be used. The transverse passage 38 may extend transversely at an angle from the upper end of the lower longitudinal slot to the lower end of the upper longitudinal slot and is defined by the surfaces or walls 380: and 38b of the body. The longitudinal slots and the transverse slot thus form a by-pass flow passage 39 through the body. A value 40 is longitudinally movably mounted on the body for movement between the closed position illustrated in FIGURES 1 and 2 and the open position illustrated in FIGURE 3 and includes a vertical rod 41 movably receivable in a longitudinal bore 43 which extends through the upper portion of the body and opens downwardly through the upper surface 38a of the body. The rod is also receivable in a semi-circular vertical groove or recess 45 in the wall 37a. A valve plate 46 having a vertical groove or channel 47 in which the valve rod is disposed is rigidly secured to the rod in a suitable manner, as by spot welding. The valve plate is of greater length or height than the height or width of the transverse passage and its upper end edge or surface 48 is of the same configuration or inclination as the wall 38a so that when the valve is in its upper position, the upper edge of the valve plate engages the wall 38a. The lower portions of the valve plate abut the wall 37a of the body when the valve is in its closed or upper position so that the valve plate then extends vertically acros the transverse slot 38 and closes the by-pass flow passage 39 to flow of fluids. The lower end of the valve rod has a hook or stop 52 which lies in a horizontal plane and whose internal curved surface 53 has a diameter substantially equal to that of the shank 19. The throat 54 of the hook opens laterally outwardly in the same direction as the lower slot 37 and is in alignment therewith. The throat 54 may be of slightly smaller width than the diameter of the shank so that the hook must be resiliently outwardly deformed to permit entry of the shank therein and so that hook will resist lateral displacement relative to the shank. A top stop 56 is detachably secured to the upper end of the valve rod by means of its threaded bore 57 thereof in which is receivable the upper threaded end portion of the operator rod. The top stop has a substantially U- shaped opening or slot 58 which is of greater width than the diameter of the shank of the sucker rod and which is in alignment with the upper longitudinal slot 36 and opens laterally outwardly in the same direction. The slot 58 is preferably of the same or greater dimensions as the upper slot 36 of the body in order that it not restrict flow of fluids from the upper slot.

The upper end portion of the body 32 has a relatively short, small beveled surface 60 to facilitate the upward .movement of the body pas-t such obstructions as the lower ends of the tubing sections 20 at the coupling recesses 21a thereof and the lower end portion of the body is provided with a similar beveled surface 61 of greater length to facilitate the downward movement of the body past such upwardly facing obstructions as the upper ends of the tubing sections at the coupling recesses.

When the well tool is to be mounted on the shank 19 of a sucker rod, the top stop is detached from the upper end of the valve rod and the assembly of the rod and the valve plate is removed from the body by downward movement relative thereto. The body 32 is then positioned on the shank 19 by holding the body at an angle to the longitudinal axis of the shank so that the transverse slot 38 is in alignment with the shank and then moving the body onto the shank until the shank is in alignment with the inner ends of the longitudinal slots 36 and 37. The valve rod is then moved through the lower slot 37 with the rod disposed in the semi-circular recess 45 and the valve plate abutting the side wall 37a to move the upper end of the operator rod through the rod bore 43 of the body until its upper threaded end portion extends outwardly of the upper end of the body. The top stop 56 is then threaded on the upper end of the rod, it being free to rotate about the rod since it is now in the position illustrated in FIGURE 7 and during such rotation will not engage the shank of the rod. When the top stop is rotated a sufficient number of times to secure it against forceable upward non-rotative removal from the rod, it is rotated to a final position wherein its slot 58 is in alignment with the upper longitudinal slot 36 of the body. The body is then rotated in a clockwise manner, as seen in FIGURE 7, until the shank is in the longitudinal bore 33 of the body, the shank passing into the slots of the top stop 56 and the bottom stop 52 of the operator rod as well as through the longitudinal slots of the body during such movement. Since the inner portions of the longitudinal slots of the body are of smaller width than the diameter of the shank, the portions of the body on opposite sides of these slots deform resiliently outwardly during such pivotal movement of the body as the side walls defining the two slots engage the shank and are cammed or forced apart by such engagement with the shank. The outwardly divergent walls or surfaces defining the longitudinal slots facilitate outward displacement or deformation of such portions of the body to permit the reception of the shank in the central longitudinal passage of the body. Such deformed portions of the body move back resiliently to their undistorted positions as illustrated in FIGURE 4 to help hold the body against displacement from the shank. The two stops 52 and 56 also aid in holding the well tool properly positioned on the body and against displacement therefrom.

The above operation is repeated in reverse sequence when it is desired to remove the well tool from the shank of a sucker rod. In removing the well tool from the shank, the valve rod is preferably first moved to a lower position on the body, and the well tool is pivoted about a transverse axis to substantially the position illustrated in FIGURE 7 whereupon the stop 56 is in position to be unscrewed from the rod. Once the top stop has been detached from the rod, the valve plate and the rod are moved downwardly out of engagement with the body whereupon a further counter-clockwise rotation of the body, during which the body resiliently deforms to permit movement of the shank into the longitudinal slots, moves the transverse passage or slot 38a of the body into alignment with the shank so that the body can then be easily removed from the shank.

Well liquids pumped through the tubing T may be of such composition that parafiin and like substances tend to separate from the fluids and deposit on the internal surfaces of the tubing and the sucker rod string, especially in the upper portions of the tubing, since the temperature of the fluids decreases as the fluids are pumped upwardly through the tubing. To prevent the deposition of such substances on the tubing and on the sucker rod string, the well tools 18 are mounted on each sucker rod of the string in the manner described. Since the external diameter of the body 32 of each well tool is substantially equal or very slightly smaller than the internal diameter of the tubing T and since the diameter of the central longitudinal bore 33 of the body is only slightly greater than the diameter of the shank, the body substantially closes the annulus between the shank of the sucker rod and the tubing into which the sucker rod string is lowered.

Assuming now that the well tool of a particular sucker rod is in its lowermost position on the shank of the rod, the stop or hook 52 is in engagement with the lower stop surface 29b of the rod and the valve 4t) is in its upper position on the valve body illustrated in FIGURES 1 and 2 closing the transverse passage 38, and thus the bypass flow passage 39, since the lower end portions of the valve plate and the adjacent portion of the rod abut the wall or surface 37a and the upper edge of the slide plate abuts the top wall 38a defining the top side of the transverse slot. The well tool thus closes or almost fully closes the annulus between the shank and the tubing to prevent or greatly restrict the flow of fluids in the tubing past the well tool.

Upon the commencement of the reciprocatory or pumping movement of the sucker rod string, the well tool on each rod is carried upwardly through the tubing with the string initially moving upwardly on its sucker rod due to the engagement of the hook 52 with the stop surface 29b of the sucker rod for a substantial distance, for example, four or six feet. When the direction of the movement of the sucker rod string is reversed, the sucker rod will move downwardly leaving the well tool in place in the well tube since the well tool now substantially closes the annulus between the string of sucker rods and the tubing and the flow of fluids past the well tool, if not entirely eliminated, is substantially restricted so that any downward movement of the well tool, which now is not supported by the support surface 1%, is very slow. Before the well tool can move any appreciable distance downwardly in the well tubing, the direction of movement of the string of tubing is reversed and causes the fluids to be pumped upwardly through the tubing beneath the well tool. Such flow of the well fluid causes the well tool to move further upwardly in the tubing and on the shank of its sucker rod. This sequence of operation during the continuous reciprocation of the string of sucker rods causes the well tool to move upwardly on the shank of its rod until its stop 56 engages the upper stop surface 29a at the upper end of its shank and further upward movement of the valve is arrested. Since the body 32 of the well tool may be moving with some velocity and since the upwardly flowing fluids continue to exert an upward force on the body, the body will move upwardly on the shank and now also relative to the now stationary valve 40 until the valve plate is in its lower open position. The by-pass flow passage is thus opened and the well tool will move downwardly by gravity in the tubing since well fluids may now flow past the body through the by-pass flow passage as the body descends in the tubing and on the shank 19 of its sucker rod. When the hook or bottom stop 52 again engages the lower stop surface 29b of the sucker rod, the body will move downwardly relative to the valve, the by-pass flow passage is again closed and the upwardly flowing fluids will again cause the well tool to move up wardly in the tubing. The above sequence of operations and upward and downward travel of the well tool on its sucker rod will be continuously repeated as long as the fluids flow upwardly in the tubing. The distance of movement of the well tool in the tubing will be considerably longer than the length of the shank of the sucker on which it is mounted since the length of the stroke, or distance of reciprocatory movement, of the string of sucker rods may be several feet, for example, six feet, so that the range of such travel or movement of the well tools 18 in the tubing may be twelve feet longer than the lengths of the shanks of the sucker rods so that ranges of movement of the well tools on adjacent rods overlap.

During the upward and downward movement of the well tools, since the string of sucker rods of course tends to vibrate or move laterally in the tubing, the bodies 32 engage the internal surfaces of the well tubing and thus dislodge any deposits of paraflin or the like which may be separating from the well fluids and collecting on the internal surfaces of the well tubing. In addition, during upward movement of the well tools since their by-pass flow passages are closed, the velocity of flow of the well fluids around the exterior of the well bodies through any extremely small passages or orifices between the outer surfaces of the bodies and the internal surfaces of the well tubing is greatly increased so that the fluids themselves also tend to remove such deposits from the well tubing in moving upwardly therepast. The small annular spaces between the shanks and the surfaces of the bodies defining the longitudinal bores 33 thereof are lubricated by the small amounts of the fliuds which flow therepast so that there is no great frictional engagement between the bodies of the well tools and the shanks of the rods. The engagement of the various surfaces of the bodies 32 with the shanks also tends to remove any parafiin or the like which may be separating from the well fluids and tending to deposit on the shanks.

The weight of the well tool 18 is sufliciently great and the dimensions of the. by-pass flow passage are such that the well tool will descend by gravity through the fluids in the tubing whenever the valve 40 is moved to its open position. Since the deposits of paraffin or the like tend to solidify and harden with time, the well tools 18 which continuously remove such deposits from the surfaces of the well tubing are very efficient and do not impose any great loads on the sucker rod string since any such deposits are obviously being removed continuously and before they have time to harden or solidify on the walls of the tubing or on the shanks of the sucker rods. Since the couplings 21 and the wrench flat portions 24 and upsets 28a or 28b of the rods at each juncture of the ends of two rods provide irregular surfaces and decrease the effective orifice of the annulus between the string S and the tubing at such points, the increased turbulence and the increased velocity of flow of the fluids flowing upwardly past such areas or locations of connections of adjacent ends of the sucker rods in the tubing inhibit the deposition of paraflin and the like from the fluids onto the extreme end portions of the sucker rods and the couplings 21.

It will thus be apparent that not only the internal surfaces of the tubing itself are maintained relatively free of deposits of parafiin and the like but that the string of sucker rods itself is also kept relatively free of such deposits and that any excessive deposits of paraffin and the like on the shanks of the sucker rods are removed by the bodies 32 of the well tools and that any films or coatings of such substances on the shanks merely serve as lubricants and facilitate the movement of the bodies 32 of the well tools 18 on such shanks.

Since the sucker rod string is made of a considerable number of such sucker rods, for example, several hundred and each sucker rod is only twenty-five or thirty feet long, the total length of the sucker rod string may be several thousand feet and since the movement of each well tool on the shank of its rod is determined by the condition of internal surfaces of the portion of well tubing in which it is reciprocated, the curvature of the tubing at such portion and such other factors, it is highly improbable that at any one time all of the valves of the many well tools 18 open at one time and close at another time simultaneously. The valves actually open and close at different random times. The column of fluids in the tubing is of course separated, staged or segmented by the well tools 18 and any gases moving out of solution from the liquids during the upward movement of the fluids through the tubing, form a relatively small pocket or short column of gas. beneath the next higher closed well tool and, when the valve of such well tool opens, such bubble or short column of gases is allowed to flow upwardly until its upward movement is stopped by another higher well tool which happens to be closed. The gases are thus never permitted to accumulate in any portion of the tubing in great volume and form a pocket or column of substantial length which could give rise to the condition known as gas lock. When such gas lock condition occurs in a tubing, the pumping of fluids to the surface is stopped due to the fact that a dynamic pressure balance is achieved between the interior of the tubing and the earth formation from which the fluids are being pumped, the gases in such long column expanding and compressing as the sucker rod and the pump actuated thereby are reciprocated.

It will now be seen that the new and improved well tool assembly 15 of the invention includes an elongate member such as a string S formed of a plurality of sections or sucker rods 16 reciprocable in a flow conductor, such as a string of tubing, for actuating a well device, such as a pump, that the elongate member is provided with a plurality of longitudinally spaced well tools which are movable through predetermined longitudinal distances on the elongate member and which close the annulus between the elongate member and the tubing, and that each well tool is provided with a by-pass flow passage and a valve means for closing the by-pass flow passage automatically operable upon the movement of each of the well tools to either extreme longitudinal position in its range of movement on the elongate member for opening and closing the valve means whereby the pressure of the fluids flowing upwardly in the tubing moves the well tools upwardly in the well tubing until they reach their uppermost extreme longitudinal position on the elongate member which then move by gravity downwardly to their extreme lower posi tions on the elongate member.

It will further be seen that during the movement of the well tool in the tubing and on the elongate member, the bodies 32 of the well tools remove the deposits of paraflin and the like from the internal surfaces of the tubing and from the elongate member and that the increased velocity of flow of fluids leaking or escaping between outer surfaces of the bodies of the well tools and the internal surfaces of the tubing also tends to remove any deposits tending to form on the internal wall surfaces of the tubing.

It will now be seen that the well tool assembly embodying the invention includes a flow conductor, such as the tubing T, an elongate member, such as the string S of sucker rods 16, reciprocably movable through a limited distance in the flow conductor and a plurality of well tools, such as the well tools 18, movably mounted on the elongate member in longitudinally spaced relation to each other and movable longitudinally through predetermined longitudinal distances or ranges on the elongate member.

It will further be seen that the elongate member is provided with a plurality of pairs of stop surfaces, such as the stop surfaces 29a and 2%, between which a well tool is movable and which define the limits of longitudinal movement of the well tools on the elongate member.

It will also be seen that the well tools have bodies which close the annulus between the elongate member and the flow conductor and that the bodies are provided with by-pass flow passages closable by valves for controlling1 the flow of fluids in the flow conductor past the well too s.

It will further be seen that the valves have operator means or stop members on opposite ends of the body engageable with the stop surfaces of the elongate member for moving the valves between their open and closed positions as the well tools reach their extreme longitudinal positions relative to the elongate member.

It will further be seen that the extreme upper limit of longitudinal movement of each well tool in the flow conductor is established by the extreme upper position of the stop surface 29a engageable by the well tool attainable in the flow conductor by the upper stop surface 29a during the reciprocal movement of the elongate member in the flow conductor and that the extreme lower limit of longitudinal movement of each well tool in the flow conductor is established by the extreme lower position of the lower stop surface 2% engageable by the well tool attainable in the flow conductor by the lower stop surface 2% during the reciprocal movement of the elongate member in the flow conductor.

The well tool assembly 110 illustrated in FIGURES 8, 9 and 10 which is usable in a well wherein the fluids are not caused to flow upwardly by a pump which is actuable by a reciprocable string of sucker rods but which fluids flow upwardly either by the pressure of the earth formation from which they are being produced or by a lifting gas injected into the tubing by the usual gas lift valves includes a flow conductor C, such as a tubing, formed of a plurality of tubing sections 111 connected at their adjacent ends by couplings 112 which form annular coupling recesses 113. Stop members or rings 114 are connected at preselected longitudinally spaced locations in the tubing at the time the tubing sections are connected to one another by being positioned between the adjacent spaced ends of a pair of adjacent tubing sections so that the outer portions of the rings extend into the coupling recess 113 and the inner portions thereof extend inwardly into the flow passage of the tubing. Each pair of adjacent stop rings may have a plurality of tubing sections therebetween.

A well tool 118 is positioned between each pair of adjacent stop rings 114 for preventing deposits of paraflin and the like or for removing such deposits from the internal walls or surfaces of the tubing between the pair of stop rings.

The well tools 118 are substantially identical in structure and mode of operation of the well tools 18, differing therefrom only in that their bodies 132 are not provided with a central longitudinal bore such as the bore 33 of the bodies 32 of the well tools 18. Accordingly, the ele ments of the well tools 118 have been provided with the same reference numerals, to which the prefix 1 has been added, as the corresponding elements of the well tools 18.

It will be apparent that the by-pass flow passage 139 of the body 132 of each well tool 118 is formed by the upper and lower longitudinal slots 136 and 137 and the transverse slot 138 and is closable by the valve 140 when the valve is in its upper position. The bottom and top stop members 152 and 156 on the opposite ends of the valve rod 141 are engageable with the lower and upper stop rings 114 between which the well tool is movable to move the valve of the well to its closed and open positions, respectively.

In use, the fluids flowing upwardly through the tubing C cause the well tools 118 whose valves 141) are in their upper closed positions closing their by-pass flow passages to move upwardly in the well tubing since the flow of fluids in the tubing past such well tools is very greatly restricted or prevented. As each upwardly moving well tool reaches the stop ring immediately thereabove, the top stop 156 of the rod of its valve 140 engages such stop ring and, as the body 132 continues to be moved upwardly by its own momentum and the force exerted thereon by the upwardly flowing fluids, the by-pass flow passage 139 is opened as the valve assumes its lower open position on the body. As soon as the by-pass flow passage is opened, the fluids flow past the well tool through the bypass flow passage and the well tool drops by gravity in the tubing until its bottom stop 152 engages the lower stop ring 114 and, since the weight of the body 132 and its mometum causes it to continue to move downwardly even though downward movement of the valve is thus arrested, the valve is caused to assume its closed position. Once the "by-pass flow passage is again closed, the force of the upwardly flowing fluids again causes the well tool to move upwardly. This sequence of operations and the reciprocal movement of the well tools continues as long the the fluids flow upwardly in the tubing. During such movement of the well tools, the

bodies 132 thereof engage the internal surfaces of the tubing and scrape or remove any deposits of paraflin or the like which may be collecting thereon. In addition, any flow of fluids past the bodies 132 through any small spaces between the outer surfaces of the bodies and the internal surfaces of the tubing during upward movement of the bodies while their valves are in closed position, is necessarily of relatively high velocity and such flow also tends to remove any such deposits from the internal surfaces of the tubing. The well tools 118 also stage or segment the column of upwardly flowing fluids since the valves of the plurality of valves open and close at random times and thus prevent the formation of large pockets or columns of gas in the upwardly flowing fluids.

It will now be apparent that both well tool assemblies 15 and include a flow conductor having a plurality of well tools reciprocably movable in the flow conductor through spaced ranges or distances, that the well tools have bodies which close the longitudinal flow passage of the flow conductor and which are provided with bypass flow passages and valves for closing the by-pass flow passages, that when the valves are in closed position the well tools are moved upwardly by the fluids flowing through the flow conductor and when the valves are in open position the well tools move downwardly in the tubing, and that the valves are provided with operator means or stops which are engageable with longitudinally spaced stop means of the Well tool assembly for moving the valves to their open positions when the well tools reach their extreme upper limits of their ranges of reciprocable movement and to their closed positions when the well tools reach their extreme lower limits of their ranges of re ciprocable movement.

It will also be seen that the well tools, when the well tool assembly includes an elongate member, such as the string S of sucker rods, which extends through the flow conductor, the bodies of the well tools are provided with longitudinal bores through Which the elongate member extends movably and that the elongate member carries the stop means for engaging the operator means of the valves of the well tools and that when the well tool assembly does not include such elongate member, the stop means are carried by the flow conductor.

It will also be apparent that while the bodies of the well tools have been shown provided with by-pass flow passages of a particular configuration and with valves of a particular structure and mode of opeart-ion, the byp-ass flow passages could be of different configuration and closeable by valves of a different type, e.g., poppet valves. The illustrated and described by-pass flow passage and valve are preferred since the pressure of the fluids does not exert any force tending to hold the valve against movement from either position to the other.

The foregoing description of the invention is explanatory only, and changes in the details of the construction illustrated may be made by those skilled in the art, within the scope of the appended claims, without departing from the spirit of the invention.

What is claimed and desired to be secured by Letters Patent is:

1. A well tool assembly including: a flow conductor having a longitudinal flow passage; and a plurality of well tools in the fl'ow conductor for removing deposits on internal surfaces of the flow conductor reciprocably movable in said passage in limited longitudinal ranges in the passage of the flow conductor, each of said well tools having valve means for closing said longitudinal passage and being movable upwardly in said range in said longitudinal passage when closing said flow passage by fluids flowing upwardly in said passage and moving downwardly in said range in said flow passage when not closing said passage, said well tools removing deposits from internal surfaces of the flow conductor during their longitudinal movement in the flow conductor, said valve meansof each of said well tools being operative to open and close said passage l. l of said well tool independently of the operation of the valve means of the others of said well tools.

2. A well tool assembly including: a flow conductor having a longitudinal flow passage and a plurality of well tools in the flow passage for removing deposits from internal surfaces of the flow conductor reciprocably movable in said passage in limited longitudinal ranges and intermittently closing the longitudinal flow passage at longitudinally spaced locations in the passage for segmenting the column of fluids flowing upwardly through the longitudinal passage, each of said well tools being operative to open and close said flow passage independently of the operation of the others of said well tools, said well tools removing deposits from internal surfaces of the flow conductor, said well tools being moved upwardly in said longitudinal passage by fluids flowing upwardly therethrough.

3. A well tool assembly including: a flow conductor having a longitudinal flow passage and a plurality of Well tools in the flow passage for removing deposits from internal surfaces of the flow conductor reciprocably movable in the flow passage in limited longitudinal ranges and intermittently closing the longitudinal flow passage at longitudinally spaced locations in the flow passage for segmenting the column of fluids flowing upwardly through the longitudinal passage, said well tools removing deposits from internal surfaces of the flow conductor during longi-.

tudinal movement therein, each of said well tools including a body having an external diameter substantially equal to the internal diameter of the flow conductor and having a by-pass flow passage for permitting flow of fluids in the flow conductor past the body, and a valve for closing said by-pass flow passage, said valve having operator means for moving said valve between a closed position closing said by-pass flow passage and an open position wherein said by-pass flow passage is open, said well tool assembly having longitudinally spaced stop means engageable by said operator means of the well tools for causing said valves to be moved to their open positions when the well tools reach upper positions in the flow conductor and for moving the valves to closed positions when the well tools reach lower positions in the flow conductor, said well tools being movable upwardly in said longitudinal passage by fluids flowing upwardly therethrough.

4. The well tool assembly of claim 3 wherein said well tool assembly includes an elongate member reciprocaibly longitudinally movable in said longitudinal passage of said flow conductor and wherein said bodies of said well tools have longitudinal bores, said elongate member extending movably through said bores of said bodies, said spaced stop means engageable by said operator means of said well tools being carried by said elongate member.

5. A well tool assembly including: a flow conductor having a longitudinal flow passage and a plurality of well tools in the flow passage for removing deposits frorn'internal surfaces of said flow conductor reciprocably mova ble in said passage in limited longitudinal ranges and in termittently closing the longitudinal flow passage at longitudinally spaced locations in the flow passage for segmenting the column of fluids flow-ing upwardly through the longitudinal passage, said well tools removing deposits from internal surfaces of the flow conductor during longitudinal movement thereof in said longitudinal passage, each of said well tools including a body having an external diameter substantially equal to the internal diameter of the flow conductor and having a by-pass flow passage for permitting flow of fluids in the flow conductor past the body, and a valve for closing said by-pass flow passage, said valve having operator means for moving said valve between a closed position closing said by-pass flow passage and an open position wherein said by-p-ass flow passage is open, said well tool assembly having longitudinally spaced stop means carried on said flow conductor engageable by said operator means of the well tools for causing said valve to be moved to their open positions when the well tools reach upper positions in the flow conductor and for moving the valves to closed positions when the well tools reach lower positions in the flow conductor said well tools being movable upwardly when said valves are in closed position by fluids flowing upwardly through said longitudinal passage.

6. A well tool assembly including: a string of interconnected sucker rods reciprocably positionable in the longitudinal flow passage of a flow conductor, each of said sucker rods including a shank and a pair of laterally outwardly extending stop surfaces at opposite ends of said shank; and well tools mounted on the shanks of at least some of said sucker rods for longitudinal movement on the shank, each of said well tools having valve means for intermittently closing the annulus between the shank and the flow conductor in which the string is reciprocably movably positionable, said well tools being movable upwardly in the longitudinal flow passage of a flow conductor by fluids flowing upwardly through the longitudinal flow passage when said valve means are in closed position.

7. A well tool assembly including: a string of interconnected suoker rods rec-iprocab-ly positionable in the longitudinal flow passage of a flow conduct-or, each of said sucker rods including a shank and a pair of laterally outwardly extending stop surfaces at opposite ends of said shank; and well tools mounted on the shanks of at least some of said sucker rods for longitudinal movement on the shank for intermittently closing the annulus between the shank and the flow conductor in which the string is reciprocably movably positionable, each of said well tools having a body provided with a by-pass flow passage for permitting flow of fluids through the longitudinal passage past the well tool, a valve for closing said by-pass flow passage and means engageable with the stop surfaces of the shank for moving said valve to its open position when the well tool reaches upper position on the shank and for closing the by-pass flow passage when the tool reaches a lower position on the shank, said well tools being movable upwardly on said shanks when said by-pass flow passages are closed by fluids flowing upwardly in said flow conductor.

8. A well tool including: a body movably positionable in a flow passage of a flow conductor for closing the flow passage thereof, said body having a by-pass flow passage for permitting movement of fluids past the body in the flow passage of a flow conductor; a valve mounted on said body for movement between a closed position wherein said valve closes said by-pass flow passage and an open position wherein said by-pass flow passage is open to flow of fluids theret-hrough; and means carried by said body and extending outwardly of opposite ends of said body for moving said valve between said open and closed positions, said body being movable upwardly in said flow passage of a flow conductor by fluids flowing upwardly therethrough when said valve is in closed position.

9. A Well tool including: a body m-ovably positionable in a flow passage of a flow conductor for closing the flow passage thereof, said body having a longitudinal bore extending the length thereof whereby said body is movably mountable on an elongate member, said body having a by-pass flow passage for permitting movement of fluids past the body in the flow passage of a flow conductor; and a valve mounted on said body for movement between a closed position wherein said valve closes said by-pass flow passage and an open position wherein said by-pass flow passage is open to flow of fluids therethrough; and means carried by said body and extending outwardly of opposite ends of said body for moving said valve between said open and closed positions, said body being movable upwardly in a flow passage of a flow conductor by fluids flowing upwardly therethrough when said valve is in closed position.

10. A well tool including: a body having a pair of diametrically opposed laterally outwardly opening longitudinal slots and having a laterally outwardly opening traverse slot connecting adjacent ends of said longitudinal slo-ts, said slots providing a by-pass flow passage longitudinally through said body; and means movable longitudinally on said body for closing said transverse slot.

11. A well tool including: a body having a pair of diametrically opposed laterally outwardly opening londitudinal slots and having a laterally outwardly opening traverse slot connecting adjacent ends of said longitudinal slots; a valve movably positioned in one of said longitudinal slots and including a valve rod, said rod extending outwardly of opposite ends of said body, said valve being movable between an upper closed position wherein it extends out of said one of said longitudinal slots into and closes said lateral transverse slot and a lower open position, said valve being movable between said open and closed positions by means of said rod.

12. A well tool including: a flow conductor having a longitudinal passage; and a plurality of well tools in the flow conductor reciprocably movable therein in limited longitudinal ranges in the passage of the flow conductor, each of said well tools having valve means for closing said longitudinal passage and being movable upwardly in said range in said longitudinal passage when closing said flow passage by fluids flowing upwardly in said passage and moving downwardly in said range in said flow passage when not closing said passage, said well tools removing deposits from internal surfaces of the flow conductor during their longitudinal movement in the flow conductor, said body having a longitudinal bore for receiving a shank of an elongate member therethrough extendable through said body, said body being mounted for limited longitudinal movement on said slots.

13. The well tool of claim 11 wherein said valve rod has operator members on opposite ends thereof, said operator members having slots opening laterally outwardly in the same direction as the slots at the ends of the body adjacent said operator members.

14. A well tool assembly including: a flow conductor having a longitudinal flow passage; and a plurality of longitudinally spaced well tools movable reciprocably independently of each other in the flow passage through predetermined ranges for removing deposits from internal surfaces of the flow conductor, said well tools being movable upwardly in said flow passage by fluids flowing upwardly therethrough.

15. The well tool assembly of claim 14, wherein each of said well tools includes a body having a by-pass flow passage and a valve for closing said by-pass flow passage, said well tools being movable upward by fluids when said by-pass flow passage is closed.

References Cited by the Examiner UNITED STATES PATENTS 627,039 6/ 1899 Youmans 103-225 1,750,851 3/1930 Meier 166-176 1,774,616 9/1930 Sherman 166-176 2,360,577 10/ 1944 Parrish 103-225 2,655,113 10/195 3 Ward 166-176 2,928,472 3/1960 Tripplehorn 166-176 CHARLES E. OCONNELL, Primary Examiner.

J. A. LEP-PINK, Assistant Examiner. 

1. A WELL TOOL ASSEMBLY INCLUDING: A FLOW CONDUCTOR HAVING A LONGITUDINAL FLOW PASSAGE; AND A PLURALITY OF WELL TOOLS IN THE FLOW CONDUCTOR FOR REMOVING DEPOSITS ON INTERNAL SURFACES OF THE FLOW CONDUCTOR RECIPROCABLY MOVABLE IN SAID PASSAGE IN LIMITED LONGITUDINAL RANGES IN THE PASSAGE OF THE FLOW CONDUCTOR, EACH OF SAID WELL TOOLS HAVING VALVE MEANS FOR CLOSING SAID LONGITUDINAL PASSAGE AND BEING MOVABLE UPWARDLY IN SAID RANGE IN SAID LONGITUDINAL PASSAGE WHEN CLOSING SAID FLOW PASSAGE BY FLUIDS FLOWING UPWARDLY IN SAID PASSAGE AND MOVING DOWNWARDLY IN SAID RANGE IN SAID FLOW PASSAGE WHEN NOT CLOSING SAID PASSAGE, SAID WELL TOOLS REMOVING DEPOSITS FROM INTERNAL SURFACES OF THE FLOW CONDUCTOR DURING THEIR LONGITUDINAL MOVEMENT IN THE FLOW CONDUCTOR, SAID VALVE MEANS OF EACH OF SAID WELL TOOLS BEING OPERTIVE TO OPEN AND CLOSE SAID PASSAGE 